1. Technical Field
This application relates to a black powder type pyrotechnic having reproducible and uniform properties and more particularly to a pyrotechnic which employs a crystalline organic substrate as a substitute for charcoal.
2 . Description of the Prior Art
Devices in accordance with the prior art in the past have been known to exhibit certain shortcomings and problems. Among the prior art problems is that although the manufacture of black powder has evolved over the years, the factors that control black powders' burning properties are not fully known and certainly not undersood. Reliability and consistency of properties have been a continuing problem.
Black powder is a mixture of approximately 75 percent potassium nitrate, 15 percent charcoal and 10 percent sulfur. It is probably the oldest known energetic material and has been used in weaponry for centuries. The inconsistency between black powder's use for so many years and the lack of knowledge about the factors that control its combustion properties is related to the nature of its composition. It is a heterogeneous mixture of three solids, pressed to about 95 percent theoretical maximum density. To add to the problem, charcoal is a naturally derived substance which contains up to 35-percent tar-like constituents (volatiles) which varies from one source to another. Such variance has been found to have a great impact on the combustion properties of black powder. Recently, poor combustion properties have been cited as a cause for weapon malfunctions. One problem of prime concern is that various lots of black powder made by a particular manufacturer and black powder made by various manufacturers, using apparently equivalent processes, produce a pyrotechnic with different combustion characteristics. In fact, it has been impossible to identify "good" and "bad" lots, in relation to device performance, without a clear understanding as to the particular differences involved. Such variances are believed to be due to the nonstandard chemical and physical properties of black powder itself. The problem is made more complex by charcoal's resistance to yield structural information by standard laboratory analyses.
The reasons for the difficulties in characterizing charcoal used in black powder are many. It is an amorphous substance; it reacts and changes on heating; it is a mixture of many components; and only small portions of it will dissolve in solvents. Since the material cannot be characterized, it has been impossible to learn what reactions might be important in combustion. An object of the present invention is to provide a single organic compound which can serve as an adequate substitute for charcoal and render the same performance, in a reproducible manner, as does "good" black powder. A further object of the invention is to provide a new type of pyrotechnic material in which a standard chemistry of combustion and uniform physical properties can be maintained.